Is there any way to tell which Gridseed is not running at maximum speed using Sandor's cpuminer? For example, in this screenshot:

http://i.imgur.com/piH2iDA.png

Gridseed #1 is running really slowly, which probably means that I need to either re-seat the heatsink or resolder the resistor. However, how do I determine which one is Gridseed #1? When I unplug the USB cable to a Gridseed, the UI doesn't update to let me know that it's dead, and every Gridseed looks like it's still hashing.